U.S. patent number 10,752,373 [Application Number 15/815,513] was granted by the patent office on 2020-08-25 for air management systems for stacked motor assemblies.
This patent grant is currently assigned to Textron Innovation Inc.. The grantee listed for this patent is Textron Innovations Inc.. Invention is credited to Kirk Landon Groninga, Daniel Bryan Robertson.
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United States Patent |
10,752,373 |
Groninga , et al. |
August 25, 2020 |
Air management systems for stacked motor assemblies
Abstract
A stacked motor assembly for an aircraft includes a forward
motor having an exhaust port and an aft motor disposed aft of the
forward motor, the aft motor having an intake port. The stacked
motor assembly includes an exhaust conduit originating from the
exhaust port of the forward motor and disposed at least partially
around the aft motor such that exhaust from the forward motor
bypasses the aft motor. The stacked motor assembly also includes an
intake conduit terminating at the intake port of the aft motor and
disposed at least partially around the forward motor such that
intake air for the aft motor bypasses the forward motor.
Inventors: |
Groninga; Kirk Landon (Keller,
TX), Robertson; Daniel Bryan (Southlake, TX) |
Applicant: |
Name |
City |
State |
Country |
Type |
Textron Innovations Inc. |
Providence |
RI |
US |
|
|
Assignee: |
Textron Innovation Inc.
(Providence, RI)
|
Family
ID: |
60629569 |
Appl.
No.: |
15/815,513 |
Filed: |
November 16, 2017 |
Prior Publication Data
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|
Document
Identifier |
Publication Date |
|
US 20190144126 A1 |
May 16, 2019 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B64D
27/24 (20130101); H02K 9/16 (20130101); B64D
35/08 (20130101); B64D 33/08 (20130101); H02K
5/20 (20130101); B64C 29/0033 (20130101); Y02T
50/60 (20130101) |
Current International
Class: |
B64D
33/08 (20060101); B64D 27/24 (20060101); B64C
29/00 (20060101); B64D 35/08 (20060101); H02K
9/16 (20060101); H02K 5/20 (20060101) |
Field of
Search: |
;244/53B |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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4413389 |
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Dec 1994 |
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DE |
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202015106564 |
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Mar 2016 |
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DE |
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2002130192 |
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May 2002 |
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JP |
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Other References
European Search Report; Application No. 17206154.1; European Patent
Office; dated Jun. 6, 2018. cited by applicant.
|
Primary Examiner: Ellis; Christopher P
Attorney, Agent or Firm: Lawrence Youst PLLC
Claims
What is claimed is:
1. A stacked motor assembly for an aircraft comprising: a forward
motor having an intake port and an exhaust port; an aft motor
disposed aft of the forward motor, the aft motor having an intake
port and an exhaust port; an exhaust conduit originating from the
exhaust port of the forward motor and disposed at least partially
around the aft motor such that exhaust from the forward motor
bypasses the aft motor; an intake conduit terminating at the intake
port of the aft motor and disposed at least partially around the
forward motor such that intake air for the aft motor bypasses the
forward motor; a forward endplate disposed forward of the forward
motor, the forward endplate forming one or more intake vents, the
intake ports of the motors operable to receive intake air via the
one or more intake vents; and an aft endplate disposed aft of the
aft motor, the aft endplate forming one or more exhaust vents, the
exhaust ports of the motors operable to emit exhaust via the one or
more exhaust vents.
2. The stacked motor assembly as recited in claim 1 wherein the
forward motor further comprises a plurality of exhaust ports and
the aft motor further comprises a plurality of intake ports;
wherein the exhaust conduit further comprises a plurality of
exhaust conduits each originating from one of the exhaust ports of
the forward motor; and wherein the intake conduit further comprises
a plurality of intake conduits each terminating at one of the
intake ports of the aft motor.
3. The stacked motor assembly as recited in claim 2 wherein the
exhaust conduits further comprise a plurality of structurally
independent exhaust hoses; and wherein the intake conduits further
comprise a plurality of structurally independent intake hoses.
4. The stacked motor assembly as recited in claim 2 wherein the
forward motor further comprises a plurality of intake ports; and
wherein the forward endplate forms a plurality of inner intake
vents and a plurality of outer intake vents, the intake ports of
the forward motor operable to receive intake air via the inner
intake vents, the intake ports of the aft motor operable to receive
intake air via the outer intake vents and the intake conduits.
5. The stacked motor assembly as recited in claim 4 wherein the
intake conduits each have a forward end coupled to the forward
endplate proximate to a respective one of the outer intake
vents.
6. The stacked motor assembly as recited in claim 2 wherein the aft
motor further comprises a plurality of exhaust ports; wherein the
aft endplate forms a plurality of inner exhaust vents and a
plurality of outer exhaust vents, the exhaust ports of the aft
motor operable to emit exhaust through the inner exhaust vents, the
exhaust ports of the forward motor operable to emit exhaust through
the outer exhaust vents via the exhaust conduits.
7. The stacked motor assembly as recited in claim 6 wherein the
exhaust conduits each have an aft end coupled to the aft endplate
proximate to a respective one of the outer exhaust vents.
8. The stacked motor assembly as recited in claim 2 wherein the
forward motor further comprises a plurality of intake ports;
wherein the motors have a common longitudinal axis; and wherein one
of the motors is rotatably disposed about the common longitudinal
axis such that the motors are rotationally offset from one another
and the intake ports of the forward motor are non-aligned with the
intake ports of the aft motor.
9. The stacked motor assembly as recited in claim 1 wherein the
motors further comprise air-cooled electric motors.
10. The stacked motor assembly as recited in claim 1 wherein the
motors each have forward and aft ends, the aft end of the forward
motor adjacent to the forward end of the aft motor.
11. The stacked motor assembly as recited in claim 10 wherein the
exhaust conduit further comprises forward and aft ends, the forward
end of the exhaust conduit coupled to the exhaust port of the
forward motor, the aft end of the exhaust conduit proximate to the
aft end of the aft motor.
12. The stacked motor assembly as recited in claim 10 wherein the
intake conduit further comprises forward and aft ends, the forward
end of the intake conduit proximate to the forward end of the
forward motor, the aft end of the intake conduit coupled to the
intake port of the aft motor.
13. The stacked motor assembly as recited in claim 1 further
comprising: a common drive shaft extending through the forward and
aft motors, the forward and aft motors operable to provide
rotational energy to the common drive shaft.
14. The stacked motor assembly as recited in claim 1 further
comprising: a housing at least partially surrounding the motors,
the housing forming a plurality of bores extending therethrough,
the plurality of bores further comprising the intake and exhaust
conduits.
15. The stacked motor assembly as recited in claim 1 further
comprising: a tail cone protruding aft of the aft motor.
16. The stacked motor assembly as recited in claim 1 wherein each
of the motors further comprise an impeller, the impeller of the
forward motor drawing intake air through the intake port of the
forward motor, the impeller of the aft motor drawing intake air
through the intake conduit and the intake port of the aft
motor.
17. An aircraft comprising: a fuselage; and a propulsion assembly
supported by the fuselage, the propulsion assembly including a
stacked motor assembly comprising: a forward motor having an intake
port and an exhaust port; an aft motor disposed aft of the forward
motor, the aft motor having an intake port and an exhaust port; an
exhaust conduit originating from the exhaust port of the forward
motor and disposed at least partially around the aft motor such
that exhaust from the forward motor bypasses the aft motor; an
intake conduit terminating at the intake port of the aft motor and
disposed at least partially around the forward motor such that
intake air for the aft motor bypasses the forward motor; a forward
endplate disposed forward of the forward motor, the forward
endplate forming one or more intake vents, the intake ports of the
motors operable to receive intake air via the one or more intake
vents; and an aft endplate disposed aft of the aft motor, the aft
endplate forming one or more exhaust vents, the exhaust ports of
the motors operable to emit exhaust via the one or more exhaust
vents.
18. The aircraft as recited in claim 17 wherein the aircraft
further comprises a tilting ducted fan aircraft and wherein the
propulsion assembly further comprises a plurality of ducted fans
tiltable relative to the fuselage.
19. The aircraft as recited in claim 17 wherein the propulsion
assembly further comprises a rotor hub assembly including a
plurality of blade assemblies; and wherein the stacked motor
assembly further comprises a common drive shaft coupled to the
rotor hub assembly and extending through the forward and aft
motors, the forward and aft motors operable to provide rotational
energy to the common drive shaft, thereby rotating the rotor hub
assembly.
Description
TECHNICAL FIELD OF THE DISCLOSURE
The present disclosure relates, in general, to air management
systems for aircraft motors and, in particular, to air management
systems for stacked motor assemblies that supply power to aircraft
propulsion systems.
BACKGROUND
An electric motor may be used by aircraft as a power source for
various functions, such as supplying rotational energy in an
aircraft propulsion system. Some electric motors cool their
internal electrical components using airflow, drawing ambient air
into the motor and exhausting the warmed air out of the motor. In
aircraft propulsion systems that utilize only a single motor, the
lack of a backup motor increases the likelihood of a crash or other
catastrophic condition should the motor fail. A single motor
propulsion system also may not meet the power demands required by
the propulsion system in the most efficient manner. Using two or
more motors in a propulsion system addresses these concerns, but
can give rise to an air management problem in which exhaust from
one of the motors is ingested by another motor. The ingestion of
exhaust by a motor may cause the motor to operate at an
unacceptably high temperature, subjecting the motor's electrical
components to higher thermal conditions and potentially affecting
the life, performance and efficiency of the motor. This air
management problem is exacerbated if one of the motors emits
exhaust toward or proximate to the intake ports of another motor.
Accordingly, a need has arisen for an air management system that
allows for the redundancy and power advantages of utilizing two or
motors in an aircraft system, while increasing motor efficiency by
facilitating the flow of ambient, non-exhaust air into the
motors.
SUMMARY
In a first aspect, the present disclosure is directed to a stacked
motor assembly for an aircraft including a forward motor having an
exhaust port and an aft motor disposed aft of the forward motor,
the aft motor having an intake port. The stacked motor assembly
includes an exhaust conduit originating from the exhaust port of
the forward motor and disposed at least partially around the aft
motor such that exhaust from the forward motor bypasses the aft
motor. The stacked motor assembly also includes an intake conduit
terminating at the intake port of the aft motor and disposed at
least partially around the forward motor such that intake air for
the aft motor bypasses the forward motor.
In some embodiments, the forward motor may include a plurality of
exhaust ports and the aft motor may include a plurality of intake
ports. In such embodiments, the exhaust conduit may include a
plurality of exhaust conduits each originating from one of the
exhaust ports of the forward motor, and the intake conduit may
include a plurality of intake conduits each terminating at one of
the intake ports of the aft motor. In certain embodiments, the
exhaust conduits may include a plurality of structurally
independent exhaust hoses, and the intake conduits may include a
plurality of structurally independent intake hoses. In some
embodiments, the forward motor may include a plurality of intake
ports and the stacked motor assembly may include a forward endplate
disposed forward of the forward motor. In such embodiments, the
forward endplate may form a plurality of inner intake vents and a
plurality of outer intake vents, the intake ports of the forward
motor operable to receive intake air via the inner intake vents,
the intake ports of the aft motor operable to receive intake air
via the outer intake vents and the intake conduits. In certain
embodiments, the intake conduits may each have a forward end
coupled to the forward endplate proximate to a respective one of
the outer intake vents. In some embodiments, the inner and outer
intake vents may form substantially concentric circles.
In certain embodiments, the aft motor may include a plurality of
exhaust ports and the stacked motor assembly may include an aft
endplate disposed aft of the aft motor. In such embodiments, the
aft endplate may form a plurality of inner exhaust vents and a
plurality of outer exhaust vents, the exhaust ports of the aft
motor operable to emit exhaust through the inner exhaust vents, the
exhaust ports of the forward motor operable to emit exhaust through
the outer exhaust vents via the exhaust conduits. In some
embodiments, the exhaust conduits may each have an aft end coupled
to the aft endplate proximate to a respective one of the outer
exhaust vents. In certain embodiments, the inner and outer exhaust
vents may form substantially concentric circles. In some
embodiments, the forward motor may include a plurality of intake
ports, the motors may have a common longitudinal axis and one of
the motors may be rotatably disposed about the common longitudinal
axis such that the motors are rotationally offset from one another
and the intake ports of the forward motor are non-aligned with the
intake ports of the aft motor. In certain embodiments, each of the
motors may be cylindrically shaped. In some embodiments, the motors
may be air-cooled electric motors. In certain embodiments, the
motors may each have forward and aft ends, and the aft end of the
forward motor may be adjacent to the forward end of the aft motor.
In some embodiments, the exhaust conduit may include forward and
aft ends. In such embodiments, the forward end of the exhaust
conduit may be coupled to the exhaust port of the forward motor,
and the aft end of the exhaust conduit may be proximate to the aft
end of the aft motor. In certain embodiments, the intake conduit
may include forward and aft ends. In such embodiments, the forward
end of the intake conduit may be proximate to the forward end of
the forward motor, and the aft end of the intake conduit may be
coupled to the intake port of the aft motor.
In some embodiments, the exhaust conduit may have an aft end and
may flare to increasing width toward the aft end. In certain
embodiments, the stacked motor assembly may include a common drive
shaft extending through the forward and aft motors. In such
embodiments, the forward and aft motors may be operable to provide
rotational energy to the common drive shaft. In some embodiments,
the stacked motor assembly may include a housing partially or fully
surrounding the motors. In such embodiments, the housing may form a
plurality of bores extending therethrough, and the bores may
include the intake and exhaust conduits. In certain embodiments,
the housing may be cylindrically shaped. In some embodiments, the
stacked motor assembly may include a tail cone protruding aft of
the aft motor. In certain embodiments, the forward motor may
include an intake port, and each of the motors may include an
impeller. In such embodiments, the impeller of the forward motor
may draw intake air through the intake port of the forward motor,
and the impeller of the aft motor may draw intake air through the
intake conduit and the intake port of the aft motor.
In a second aspect, the present disclosure is directed to an
aircraft including a fuselage and a propulsion assembly supported
by the fuselage. The propulsion assembly includes a stacked motor
assembly, which includes a forward motor having an exhaust port and
an aft motor disposed aft of the forward motor, the aft motor
having an intake port. The stacked motor assembly includes an
exhaust conduit originating from the exhaust port of the forward
motor and disposed at least partially around the aft motor such
that exhaust from the forward motor bypasses the aft motor. The
stacked motor assembly also includes an intake conduit terminating
at the intake port of the aft motor and disposed at least partially
around the forward motor such that intake air for the aft motor
bypasses the forward motor.
In some embodiments, the aircraft may be a tilting ducted fan
aircraft and the propulsion assembly may include a plurality of
ducted fans tiltable relative to the fuselage. In certain
embodiments, the propulsion assembly may include a rotor hub
assembly having a plurality of blade assemblies. In such
embodiments, the stacked motor assembly may include a common drive
shaft coupled to the rotor hub assembly and extending through the
forward and aft motors, the forward and aft motors operable to
provide rotational energy to the common drive shaft, thereby
rotating the rotor hub assembly. In some embodiments, the power
output, shape and size of the forward motor may be approximately
equal to the power output, shape and size of the aft motor. In
certain embodiments, the stacked motor assembly may include a
forward endplate disposed forward of the forward motor. In such
embodiments, the forward endplate may form one or more intake
vents, and the intake ports of the motors may be operable to
receive intake air via the intake vents. In some embodiments, the
stacked motor assembly may include an aft endplate disposed aft of
the aft motor. In such embodiments, the aft endplate may form one
or more exhaust vents, and the exhaust ports of the motors may be
operable to emit exhaust via the one or more exhaust vents.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the features and advantages of
the present disclosure, reference is now made to the detailed
description along with the accompanying figures in which
corresponding numerals in the different figures refer to
corresponding parts and in which:
FIGS. 1A-1B are schematic illustrations of a tilting ducted fan
aircraft utilizing stacked motor assemblies in accordance with
embodiments of the present disclosure;
FIGS. 2A-2H are various views of a stacked motor assembly in
accordance with embodiments of the present disclosure; and
FIG. 3 is an isometric view of a stacked motor assembly in
accordance with embodiments of the present disclosure.
DETAILED DESCRIPTION
While the making and using of various embodiments of the present
disclosure are discussed in detail below, it should be appreciated
that the present disclosure provides many applicable inventive
concepts, which can be embodied in a wide variety of specific
contexts. The specific embodiments discussed herein are merely
illustrative and do not delimit the scope of the present
disclosure. In the interest of clarity, all features of an actual
implementation may not be described in this specification. It will
of course be appreciated that in the development of any such actual
embodiment, numerous implementation-specific decisions must be made
to achieve the developer's specific goals, such as compliance with
system-related and business-related constraints, which will vary
from one implementation to another. Moreover, it will be
appreciated that such a development effort might be complex and
time-consuming but would nevertheless be a routine undertaking for
those of ordinary skill in the art having the benefit of this
disclosure.
In the specification, reference may be made to the spatial
relationships between various components and to the spatial
orientation of various aspects of components as the devices are
depicted in the attached drawings. However, as will be recognized
by those skilled in the art after a complete reading of the present
disclosure, the devices, members, apparatuses, and the like
described herein may be positioned in any desired orientation.
Thus, the use of terms such as "above," "below," "upper," "lower"
or other like terms to describe a spatial relationship between
various components or to describe the spatial orientation of
aspects of such components should be understood to describe a
relative relationship between the components or a spatial
orientation of aspects of such components, respectively, as the
devices described herein may be oriented in any desired direction.
As used herein, the term "coupled" may include direct or indirect
coupling by any means, including by mere contact or by moving
and/or non-moving mechanical connections.
Referring to FIGS. 1A-1B in the drawings, a tilting ducted fan
aircraft is schematically illustrated and generally designated 10.
Tilting ducted fan aircraft 10 includes a fuselage 12. Left and
right wings 14, 16 extend from the left and right sides of fuselage
12, respectively, although in other embodiments tilting ducted fan
aircraft 10 may employ a single wing spanning both sides of
fuselage 12. Fuselage 12 supports propulsion assemblies 18, 20,
which are coupled to wings 14, 16, respectively. In particular, a
left ducted fan 22 is rotatably coupled to the distal end of left
wing 14. Likewise, a right ducted fan 24 is rotatably coupled to
the distal end of right wing 16. Each ducted fan 22, 24 includes a
duct 26, 28 that surrounds, or partially encloses, rotor hub
assemblies 30, 32 from which a plurality of rotor blade assemblies
34, 36 radially extend, respectively. Rotor blade assemblies 34, 36
can be collectively manipulated to selectively control direction,
thrust and lift of tilting ducted fan aircraft 10. Indeed, the
collective pitch of rotor blade assemblies 34, 36 may be
independently controlled from one another to allow for differential
thrust output by ducted fans 22, 24. For example, the collective
pitch of rotor blade assemblies 34 of ducted fan 22 may be higher
or lower than the collective pitch of rotor blade assemblies 36 of
ducted fan 24 such that the thrust generated by each ducted fan 22,
24 differs from one another.
Ducted fans 22, 24 are each tiltable, relative to fuselage 12,
between a horizontal position, as shown in FIG. 1A, and a vertical
position, as shown in FIG. 1B. Ducted fans 22, 24 are in the
horizontal position during vertical takeoff and landing mode.
Vertical takeoff and landing mode may be considered to include
hover operations of tilting ducted fan aircraft 10. Ducted fans 22,
24 are in the vertical position during forward flight mode, in
which tilting ducted fan aircraft 10 is in forward flight. In
forward flight mode, ducted fans 22, 24 direct their respective
thrusts in the aft direction to propel tilting ducted fan aircraft
10 forward. Tilting ducted fan aircraft 10 is operable to fly in
all directions during the vertical takeoff and landing mode
configuration of FIG. 1A, although faster forward flight is
achievable while in the forward flight mode configuration of FIG.
1B. Ducted fans 22, 24 may be tiltable between the vertical and
horizontal positions by a rotatable shaft (not shown) extending
through wings 14, 16, and which are rotatable in response to
commands originating from a pilot and/or a flight control
system.
Propulsion assembly 18 utilizes a stacked motor assembly 38 as a
power source to rotate rotor hub assembly 30. Stacked motor
assembly 38 includes a forward motor 40 and an aft motor 42. A
common drive shaft 44, which is coupled to rotor hub assembly 30,
extends through forward and aft motors 40, 42. Forward and aft
motors 40, 42 provide rotational energy to common drive shaft 44 to
rotate rotor hub assembly 30. Forward and aft motors 40, 42 are
each air-cooled electric motors that have a forward face, into
which ambient, cooled air is drawn, and an aft face, out of which
exhaust is emitted. Because forward and aft motors 40, 42 have a
stacked configuration, in the absence of the illustrative
embodiments, aft motor 42 is subjected to ingesting the exhaust
emitted from forward motor 40, thus causing aft motor 42 to operate
at a higher temperature, subjecting the internal electrical
components of aft motor 42 to higher thermal conditions and
potentially affecting the life, performance and efficiency of aft
motor 42. The illustrative embodiments address this issue by
providing an air management system 46, which includes one or more
air conduits, to direct ambient cooling air to forward and aft
motors 40, 42 while diverting exhaust emitted from forward motor 40
around aft motor 42. By facilitating the movement of air around and
through a stacked motor assembly in each propulsion assembly 18,
20, tilting ducted fan aircraft 10 benefits from the capability of
utilizing two motors for each propulsion assembly 18, 20, each of
which harnesses boosted power and has redundancy in case one of the
motors in the stacked motor assembly fails. Propulsion assembly 18,
which includes stacked motor assembly 38 and air management system
46, is substantially similar to propulsion assembly 20, which also
includes a stacked motor assembly and an air management system.
Therefore, for sake of efficiency, certain features have been
disclosed only with regard to propulsion assembly 18. One having
ordinary skill in the art, however, will fully appreciate an
understanding of propulsion assembly 20 based upon the disclosure
herein of propulsion assembly 18.
It should be appreciated that tilting ducted fan aircraft 10 is
merely illustrative of a variety of aircraft that can implement the
embodiments disclosed herein. Indeed, stacked motor assembly 38,
including air management system 46, may be used on any aircraft
that utilizes motors. Other aircraft implementations can include
hybrid aircraft, tiltrotor aircraft, quad tiltrotor aircraft,
unmanned aircraft, gyrocopters, airplanes, helicopters, commuter
aircraft, electric aircraft, hybrid-electric aircraft, ducted fan
aircraft having any number of ducted fans, tiltwing aircraft,
including tiltwing aircraft having one or more interwing linkages,
and the like. As such, those skilled in the art will recognize that
stacked motor assembly 38, including air management system 46, can
be integrated into a variety of aircraft configurations. It should
be appreciated that even though aircraft are particularly
well-suited to implement the embodiments of the present disclosure,
non-aircraft vehicles and devices can also implement the
embodiments.
Referring to FIGS. 2A-2H in the drawings, a stacked motor assembly
is schematically illustrated and generally designated 100. Stacked
motor assembly 100 includes forward motor 102 and aft motor 104
disposed behind or aft of forward motor 102. Forward and aft motors
102, 104 each have a forward end 106, 108 and an aft end 110, 112,
respectively. Aft end 110 of forward motor 102 is adjacent or
proximate to forward end 108 of aft motor 104. Forward and aft
motors 102, 104 are air-cooled electric motors. Other types of
fluid-cooled motors may also be used in stacked motor assembly 100.
Forward and aft motors 102, 104 are each cylindrically shaped, but
may have any shape or size in other embodiments. In one
non-limiting example, forward and aft motors 102, 104 may each have
a diameter in a range between 8 to 16 inches, such as 12 inches,
and a depth in a range between 5 to 13 inches, such as 9 inches.
The size of forward and aft motors 102, 104 may depend on the
particular system in which stacked motor assembly 100 is utilized.
Any model of electric motor may be used in stacked motor assembly
100. In one non-limiting example, forward and aft motors 102, 104
may be Safran electric motors having a power output in a range
between 30 and 70 horsepower, such as 50 horsepower, or in a range
between 20 and 50 kilowatts, such as 35 kilowatts. The model, power
output, shape and size of forward motor 102 are approximately equal
or similar to the model, power output, shape and size of aft motor
104. In other embodiments, the model, power output, shape and size
of forward motor 102 may differ from the model, power output, shape
and size of aft motor 104. Tail cone 114 protrudes aft of aft motor
104. In other embodiments, stacked motor assembly 100 may lack tail
cone 114 and/or include a nose cone or spinner (not shown).
As best seen in FIG. 2E, forward end 106 of forward motor 102
includes intake ports 116 and aft end 110 of forward motor 102
includes exhaust ports 118. As best seen in FIG. 2F, forward end
108 of aft motor 104 includes intake ports 120 and aft end 112 of
aft motor 104 includes exhaust ports 122. While forward and aft
motors 102, 104 are each illustrated as having eight intake ports
and eight exhaust ports, forward and aft motors 102, 104 may have
any number of intake and exhaust ports. Forward and aft motors 102,
104 each include an impeller 124, 126, respectively. Impellers 124,
126 draw intake, or ambient, air through intake ports 116, 120 of
forward and aft motors 102, 104, respectively, thereby cooling the
internal electronics of forward and aft motors 102, 104 with
airflow. Impellers 124, 126 may rotate with a common drive shaft
128, which extends through forward and aft motors 102, 104 along a
central, and common, longitudinal axis 130 of forward and aft
motors 102, 104. Forward and aft motors 102, 104 provide rotational
energy to common drive shaft 128, which may be used to rotate any
part of an aircraft, such as a rotor hub assembly. Common drive
shaft 128 may be a single drive shaft extending through forward and
aft motors 102, 104, or may be formed from two or more shaft
segments coupled to one another.
Stacked motor assembly 100 includes a cylindrical housing 132
surrounding the sides of forward and aft motors 102, 104. Housing
132 is shown in isolation, in a cross-sectional isometric view, in
FIGS. 2G and 2H. Housing 132 includes a spacer 134 that provides a
predetermined amount of space between forward and aft motors 102,
104. Housing 132 includes bores 136 extending therethrough, which
act as a manifold for an air management system 138. Bores 136
include exhaust conduits 140 and intake conduits 142. Each exhaust
conduit 140 originates from a respective exhaust port 118 of
forward motor 102 and is disposed at least partially around aft
motor 104 such that exhaust from forward motor 102 bypasses, or is
diverted around, aft motor 104. Each exhaust conduit 140 has a
forward end 144 coupled to a respective exhaust port 118 of forward
motor 102. Aft ends 146 of exhaust conduits 140 are proximate to
aft end 112 of aft motor 104. Each intake conduit 142 terminates at
a respective intake port 120 of aft motor 104 and is disposed at
least partially around forward motor 102 such that intake air for
aft motor 104 bypasses, or is diverted around, forward motor 102.
Impeller 126 draws intake air through intake conduits 142 and
intake ports 120 of aft motor 104. Forward ends 148 of intake
conduits 142 are proximate to forward end 106 of forward motor 102.
Each intake conduit 142 has an aft end 150 coupled to a respective
intake port 120 of aft motor 104.
While the illustrated embodiment includes eight exhaust conduits
140 and eight intake conduits 142, air management system 138 may
include any number of exhaust and intake conduits, which may depend
on the number of intake ports 116, 120 and exhaust ports 118, 122
of forward and aft motors 102, 104. While exhaust conduits 140 and
intake conduits 142 are shown to have a generally flat shape to
contour the sides of forward and aft motors 102, 104, exhaust
conduits 140 and intake conduits 142 may have any cross-sectional
shape, such as a circular, elliptical, polygonal, irregular or
other cross-sectional shape. Also, housing 132 may have any
cross-sectional shape, such as an elliptical, polygonal, irregular
or other cross-sectional shape.
Forward and aft motors 102, 104 are disposed within housing 132
such that forward and aft motors 102, 104 are rotationally offset,
or clocked, relative to one another. Thus, intake ports 116 of
forward motor 102 are not aligned with intake ports 120 of aft
motor 104. Similarly, exhaust ports 118 of forward motor 102 are
not aligned with exhaust ports 122 of aft motor 104. By
rotationally offsetting forward and aft motors 102, 104 in this
manner, exhaust conduits 140 and intake conduits 142 can be
spatially disposed around forward and aft motors 102, 104 so as to
not interfere or intersect with one another. To facilitate the
emission of exhaust from forward motor 102, exhaust conduits 140
may flare to increasing width toward aft ends 146 of exhaust
conduits 140.
Stacked motor assembly 100 includes a forward endplate 152, through
which common drive shaft 128 is disposed. Forward endplate 152 is
disposed forward of forward motor 102. Forward endplate 152 forms
inner intake vents 154 and outer intake vents 156. Inner intake
vents 154 and outer intake vents 156 form substantially concentric
circles. Intake ports 116 of forward motor 102 receive intake air
via inner intake vents 154. Intake ports 120 of aft motor 104
receive intake air via outer intake vents 156 and intake conduits
142. Each forward end 148 of intake conduits 142 is coupled to
forward endplate 152 proximate to a respective one of outer intake
vents 156.
Stacked motor assembly 100 also includes an aft endplate 158
disposed aft of aft motor 104. Aft endplate 158 forms inner exhaust
vents 160 and outer exhaust vents 162, which form substantially
concentric circles. Exhaust ports 122 of aft motor 104 emit exhaust
through inner exhaust vents 160. Exhaust ports 118 of forward motor
102 emit exhaust through outer exhaust vents 162 via exhaust
conduits 140. Each aft end 146 of exhaust conduits 140 is coupled
to aft endplate 158 proximate to a respective one of outer exhaust
vents 162. In some embodiments, tail cone 114 may protrude aft from
aft endplate 158. Forward and aft endplates 152, 158 may have any
shape or size dependent upon the shape and size of stacked motor
assembly 100. In one non-limiting example, forward and aft
endplates 152, 158 may each have a diameter in a range between 14
and 22 inches, such as 18.5 inches. Air management system 138
allows for end-to-end stacking of motors 102, 104. Stacked motor
assembly 100, by virtue of having more than one motor, provides
increased rotational energy to common drive shaft 128, as may be
required in some propulsion systems. Stacked motor assembly 100
also provides redundancy in case either motor 102, 104 fails,
thereby allowing for a safe landing in case of motor failure and
preventing the aircraft from having to shut off other motors or
propellers to maintain balance.
Referring to FIG. 3 in the drawings, a stacked motor assembly for
an aircraft is schematically illustrated and generally designated
200. Stacked motor assembly 200 includes forward and aft motors
202, 204 for which airflow is managed by air management system 206.
In contrast to the embodiment illustrated in FIGS. 2A-2H, in which
the exhaust and intake conduits are bored through a housing,
exhaust conduits 208 and intake conduits 210 are structurally
independent exhaust hoses and intake hoses, or plenums,
respectively. Exhaust hoses 208 and intake hoses 210 may be formed
and positioned so as to provide structural support to stacked motor
assembly 200. Exhaust hoses 208 and intake hoses 210 may have any
cross-sectional shape, such as the flattened contoured shape shown
in FIG. 3 or a different shape. Aft ends 212 of exhaust hoses 208
are flared to facilitate the emission of exhaust from forward motor
202.
The foregoing description of embodiments of the disclosure has been
presented for purposes of illustration and description. It is not
intended to be exhaustive or to limit the disclosure to the precise
form disclosed, and modifications and variations are possible in
light of the above teachings or may be acquired from practice of
the disclosure. The embodiments were chosen and described in order
to explain the principals of the disclosure and its practical
application to enable one skilled in the art to utilize the
disclosure in various embodiments and with various modifications as
are suited to the particular use contemplated. Other substitutions,
modifications, changes and omissions may be made in the design,
operating conditions and arrangement of the embodiments without
departing from the scope of the present disclosure. Such
modifications and combinations of the illustrative embodiments as
well as other embodiments will be apparent to persons skilled in
the art upon reference to the description. It is, therefore,
intended that the appended claims encompass any such modifications
or embodiments.
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